Re: [PATCH net-next v7 00/11] net: Improve netns handling in rtnetlink
From: Xiao Liang <hidden>
Date: 2025-01-07 12:53:58
Also in:
batman, bpf, bridge, linux-can, linux-kselftest, linux-rdma, lkml, netdev
On Tue, Jan 7, 2025 at 4:57 PM Kuniyuki Iwashima [off-list ref] wrote: [...]
quoted hunk ↗ jump to hunk
We can fix this by linking the dev to the socket's netns and clean them up in __net_exit hook as done in bareudp and geneve. ---8<---diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index 89a996ad8cd0..77638a815873 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c@@ -70,6 +70,7 @@ struct pdp_ctx { /* One instance of the GTP device. */ struct gtp_dev { struct list_head list; + struct list_head sock_list; struct sock *sk0; struct sock *sk1u;@@ -102,6 +103,7 @@ static unsigned int gtp_net_id __read_mostly; struct gtp_net { struct list_head gtp_dev_list; + struct list_head gtp_sock_list;
After a closer look at the GTP driver, I'm confused about the gtp_dev_list here. GTP device is linked to this list at creation time, but netns can be changed afterwards. The list is used in gtp_net_exit_batch_rtnl(), but to my understanding net devices can already be deleted in default_device_exit_batch() by default. And I wonder if the use in gtp_genl_dump_pdp() can be replaced by something like for_each_netdev_rcu().
quoted hunk ↗ jump to hunk
}; static u32 gtp_h_initval;@@ -1526,6 +1528,10 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev, gn = net_generic(dev_net(dev), gtp_net_id); list_add_rcu(>p->list, &gn->gtp_dev_list); + + gn = net_generic(src_net, gtp_net_id); + list_add(>p->sock_list, &gn->gtp_sock_list); + dev->priv_destructor = gtp_destructor; netdev_dbg(dev, "registered new GTP interface\n");@@ -1552,6 +1558,7 @@ static void gtp_dellink(struct net_device *dev, struct list_head *head) pdp_context_delete(pctx); list_del_rcu(>p->list); + list_del(>p->sock_list); unregister_netdevice_queue(dev, head); }@@ -2465,6 +2472,8 @@ static int __net_init gtp_net_init(struct net *net) struct gtp_net *gn = net_generic(net, gtp_net_id); INIT_LIST_HEAD(&gn->gtp_dev_list); + INIT_LIST_HEAD(&gn->gtp_sock_list); + return 0; }@@ -2475,9 +2484,12 @@ static void __net_exit gtp_net_exit_batch_rtnl(struct list_head *net_list, list_for_each_entry(net, net_list, exit_list) { struct gtp_net *gn = net_generic(net, gtp_net_id); - struct gtp_dev *gtp; + struct gtp_dev *gtp, *next; + + list_for_each_entry_safe(gtp, next, &gn->gtp_dev_list, list) + gtp_dellink(gtp->dev, dev_to_kill); - list_for_each_entry(gtp, &gn->gtp_dev_list, list) + list_for_each_entry_safe(gtp, next, &gn->gtp_sock_list, sock_list) gtp_dellink(gtp->dev, dev_to_kill); } } ---8<---